Merged interactive email interface

14 files changed, 972 insertions, 341 deletions

diff --git a/libbe/arch.py b/libbe/arch.py
index 2f45aa9..1bdc8ae 100644
--- a/libbe/arch.py
+++ b/libbe/arch.py
@@ -176,7 +176,6 @@ class Arch(RCS):
         self._get_archive_project_name(root)
 
         return root
-
     def _get_archive_name(self, root):
         status,output,error = self._u_invoke_client("archives")
         lines = output.split('\n')
@@ -188,7 +187,6 @@ class Arch(RCS):
             if os.path.realpath(location) == os.path.realpath(root):
                 self._archive_name = archive
         assert self._archive_name != None
-
     def _get_archive_project_name(self, root):
         # get project names
         status,output,error = self._u_invoke_client("tree-version", directory=root)
@@ -281,6 +279,16 @@ class Arch(RCS):
         assert revpath.startswith(self._archive_project_name()+'--')
         revision = revpath[len(self._archive_project_name()+'--'):]
         return revpath
+    def _rcs_revision_id(self, index):
+        status,output,error = self._u_invoke_client("logs")
+        logs = output.splitlines()
+        first_log = logs.pop(0)
+        assert first_log == "base-0", first_log
+        try:
+            log = logs[index]
+        except IndexError:
+            return None
+        return "%s--%s" % (self._archive_project_name(), log)
 
 class CantAddFile(Exception):
     def __init__(self, file):
diff --git a/libbe/bug.py b/libbe/bug.py
index c1e5481..7554318 100644
--- a/libbe/bug.py
+++ b/libbe/bug.py
@@ -33,6 +33,11 @@ import comment
 import utility
 
 
+class DiskAccessRequired (Exception):
+    def __init__(self, goal):
+        msg = "Cannot %s without accessing the disk" % goal
+        Exception.__init__(self, msg)
+
 ### Define and describe valid bug categories
 # Use a tuple of (category, description) tuples since we don't have
 # ordered dicts in Python yet http://www.python.org/dev/peps/pep-0372/
@@ -245,10 +250,13 @@ class Bug(settings_object.SavedSettingsObject):
     def __repr__(self):
         return "Bug(uuid=%r)" % self.uuid
 
-    def set_sync_with_disk(self, value):
-        self.sync_with_disk = value
-        for comment in self.comments():
-            comment.set_sync_with_disk(value)
+    def __str__(self):
+        return self.string(shortlist=True)
+
+    def __cmp__(self, other):
+        return cmp_full(self, other)
+
+    # serializing methods
 
     def _setting_attr_string(self, setting):
         value = getattr(self, setting)
@@ -331,11 +339,7 @@ class Bug(settings_object.SavedSettingsObject):
             output = bugout
         return output
 
-    def __str__(self):
-        return self.string(shortlist=True)
-
-    def __cmp__(self, other):
-        return cmp_full(self, other)
+    # methods for saving/loading/acessing settings and properties.
 
     def get_path(self, name=None):
         my_dir = os.path.join(self.bugdir.get_path("bugs"), self.uuid)
@@ -344,30 +348,25 @@ class Bug(settings_object.SavedSettingsObject):
         assert name in ["values", "comments"]
         return os.path.join(my_dir, name)
 
+    def set_sync_with_disk(self, value):
+        self.sync_with_disk = value
+        for comment in self.comments():
+            comment.set_sync_with_disk(value)
+
     def load_settings(self):
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("load settings")
         self.settings = mapfile.map_load(self.rcs, self.get_path("values"))
         self._setup_saved_settings()
 
-    def load_comments(self, load_full=True):
-        if load_full == True:
-            # Force a complete load of the whole comment tree
-            self.comment_root = self._get_comment_root(load_full=True)
-        else:
-            # Setup for fresh lazy-loading.  Clear _comment_root, so
-            # _get_comment_root returns a fresh version.  Turn of
-            # syncing temporarily so we don't write our blank comment
-            # tree to disk.
-            self.sync_with_disk = False
-            self.comment_root = None
-            self.sync_with_disk = True
-
     def save_settings(self):
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("save settings")
         assert self.summary != None, "Can't save blank bug"
-        
         self.rcs.mkdir(self.get_path())
         path = self.get_path("values")
         mapfile.map_save(self.rcs, path, self._get_saved_settings())
-        
+
     def save(self):
         """
         Save any loaded contents to disk.  Because of lazy loading of
@@ -378,15 +377,39 @@ class Bug(settings_object.SavedSettingsObject):
         calling this method will just waste time (unless something
         else has been messing with your on-disk files).
         """
+        sync_with_disk = self.sync_with_disk
+        if sync_with_disk == False:
+            self.set_sync_with_disk(True)
         self.save_settings()
         if len(self.comment_root) > 0:
             comment.saveComments(self)
+        if sync_with_disk == False:
+            self.set_sync_with_disk(False)
+
+    def load_comments(self, load_full=True):
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("load comments")
+        if load_full == True:
+            # Force a complete load of the whole comment tree
+            self.comment_root = self._get_comment_root(load_full=True)
+        else:
+            # Setup for fresh lazy-loading.  Clear _comment_root, so
+            # _get_comment_root returns a fresh version.  Turn of
+            # syncing temporarily so we don't write our blank comment
+            # tree to disk.
+            self.sync_with_disk = False
+            self.comment_root = None
+            self.sync_with_disk = True
 
     def remove(self):
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("remove")
         self.comment_root.remove()
         path = self.get_path()
         self.rcs.recursive_remove(path)
     
+    # methods for managing comments
+
     def comments(self):
         for comment in self.comment_root.traverse():
             yield comment
@@ -489,8 +512,12 @@ def cmp_attr(bug_1, bug_2, attr, invert=False):
         return cmp(val_1, val_2)
 
 # alphabetical rankings (a < z)
+cmp_uuid = lambda bug_1, bug_2 : cmp_attr(bug_1, bug_2, "uuid")
 cmp_creator = lambda bug_1, bug_2 : cmp_attr(bug_1, bug_2, "creator")
 cmp_assigned = lambda bug_1, bug_2 : cmp_attr(bug_1, bug_2, "assigned")
+cmp_target = lambda bug_1, bug_2 : cmp_attr(bug_1, bug_2, "target")
+cmp_reporter = lambda bug_1, bug_2 : cmp_attr(bug_1, bug_2, "reporter")
+cmp_summary = lambda bug_1, bug_2 : cmp_attr(bug_1, bug_2, "summary")
 # chronological rankings (newer < older)
 cmp_time = lambda bug_1, bug_2 : cmp_attr(bug_1, bug_2, "time", invert=True)
 
@@ -512,7 +539,8 @@ def cmp_comments(bug_1, bug_2):
     return 0
 
 DEFAULT_CMP_FULL_CMP_LIST = \
-    (cmp_status,cmp_severity,cmp_assigned,cmp_time,cmp_creator,cmp_comments)
+    (cmp_status, cmp_severity, cmp_assigned, cmp_time, cmp_creator,
+     cmp_reporter, cmp_target, cmp_comments, cmp_summary, cmp_uuid)
 
 class BugCompoundComparator (object):
     def __init__(self, cmp_list=DEFAULT_CMP_FULL_CMP_LIST):
diff --git a/libbe/bugdir.py b/libbe/bugdir.py
index f7345fd..1bb307c 100644
--- a/libbe/bugdir.py
+++ b/libbe/bugdir.py
@@ -17,11 +17,12 @@
 # You should have received a copy of the GNU General Public License along
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+import copy
+import errno
 import os
 import os.path
-import errno
+import sys
 import time
-import copy
 import unittest
 import doctest
 
@@ -68,6 +69,11 @@ class NoBugMatches(KeyError):
         KeyError.__init__(self, msg)
         self.shortname = shortname
 
+class DiskAccessRequired (Exception):
+    def __init__(self, goal):
+        msg = "Cannot %s without accessing the disk" % goal
+        Exception.__init__(self, msg)
+
 
 TREE_VERSION_STRING = "Bugs Everywhere Tree 1 0\n"
 
@@ -105,7 +111,8 @@ class BugDir (list, settings_object.SavedSettingsObject):
     all bugs/comments/etc. that have been loaded into memory.  If
     you've been living in memory and want to move to
     .sync_with_disk==True, but you're not sure if anything has been
-    changed in memoryy, a call to save() is a safe move.
+    changed in memory, a call to save() immediately before the
+    .set_sync_with_disk(True) call is a safe move.
 
     Regardless of .sync_with_disk, a call to .save() will write out
     all the contents that the BugDir instance has loaded into memory.
@@ -113,9 +120,8 @@ class BugDir (list, settings_object.SavedSettingsObject):
     changes, this .save() call will be a waste of time.
 
     The BugDir will only load information from the file system when it
-    loads new bugs/comments that it doesn't already have in memory, or
-    when it explicitly asked to do so (e.g. .load() or
-    __init__(from_disk=True)).
+    loads new settings/bugs/comments that it doesn't already have in
+    memory and .sync_with_disk == True.
 
     Allow RCS initialization
     ========================
@@ -286,8 +292,7 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
 
     def __init__(self, root=None, sink_to_existing_root=True,
                  assert_new_BugDir=False, allow_rcs_init=False,
-                 manipulate_encodings=True,
-                 from_disk=False, rcs=None):
+                 manipulate_encodings=True, from_disk=False, rcs=None):
         list.__init__(self)
         settings_object.SavedSettingsObject.__init__(self)
         self._manipulate_encodings = manipulate_encodings
@@ -316,15 +321,13 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
             self.rcs = rcs
             self._setup_user_id(self.user_id)
 
-    def set_sync_with_disk(self, value):
-        self.sync_with_disk = value
-        for bug in self:
-            bug.set_sync_with_disk(value)
+    # methods for getting the BugDir situated in the filesystem
 
     def _find_root(self, path):
         """
         Search for an existing bug database dir and it's ancestors and
-        return a BugDir rooted there.
+        return a BugDir rooted there.  Only called by __init__, and
+        then only if sink_to_existing_root == True.
         """
         if not os.path.exists(path):
             raise NoRootEntry(path)
@@ -340,7 +343,77 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
                 raise NoBugDir(path)
             return beroot
 
+    def _guess_rcs(self, allow_rcs_init=False):
+        """
+        Only called by __init__.
+        """
+        deepdir = self.get_path()
+        if not os.path.exists(deepdir):
+            deepdir = os.path.dirname(deepdir)
+        new_rcs = rcs.detect_rcs(deepdir)
+        install = False
+        if new_rcs.name == "None":
+            if allow_rcs_init == True:
+                new_rcs = rcs.installed_rcs()
+                new_rcs.init(self.root)
+        return new_rcs
+
+    # methods for saving/loading/accessing settings and properties.
+
+    def get_path(self, *args):
+        """
+        Return a path relative to .root.
+        """
+        my_dir = os.path.join(self.root, ".be")
+        if len(args) == 0:
+            return my_dir
+        assert args[0] in ["version", "settings", "bugs"], str(args)
+        return os.path.join(my_dir, *args)
+
+    def _get_settings(self, settings_path, for_duplicate_bugdir=False):
+        allow_no_rcs = not self.rcs.path_in_root(settings_path)
+        if allow_no_rcs == True:
+            assert for_duplicate_bugdir == True
+        if self.sync_with_disk == False and for_duplicate_bugdir == False:
+            # duplicates can ignore this bugdir's .sync_with_disk status
+            raise DiskAccessRequired("_get settings")
+        try:
+            settings = mapfile.map_load(self.rcs, settings_path, allow_no_rcs)
+        except rcs.NoSuchFile:
+            settings = {"rcs_name": "None"}
+        return settings
+
+    def _save_settings(self, settings_path, settings,
+                       for_duplicate_bugdir=False):
+        allow_no_rcs = not self.rcs.path_in_root(settings_path)
+        if allow_no_rcs == True:
+            assert for_duplicate_bugdir == True
+        if self.sync_with_disk == False and for_duplicate_bugdir == False:
+            # duplicates can ignore this bugdir's .sync_with_disk status
+            raise DiskAccessRequired("_save settings")
+        self.rcs.mkdir(self.get_path(), allow_no_rcs)
+        mapfile.map_save(self.rcs, settings_path, settings, allow_no_rcs)
+
+    def load_settings(self):
+        self.settings = self._get_settings(self.get_path("settings"))
+        self._setup_saved_settings()
+        self._setup_user_id(self.user_id)
+        self._setup_encoding(self.encoding)
+        self._setup_severities(self.severities)
+        self._setup_status(self.active_status, self.inactive_status)
+        self.rcs = rcs.rcs_by_name(self.rcs_name)
+        self._setup_user_id(self.user_id)
+
+    def save_settings(self):
+        settings = self._get_saved_settings()
+        self._save_settings(self.get_path("settings"), settings)
+
     def get_version(self, path=None, use_none_rcs=False):
+        """
+        Requires disk access.
+        """
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("get version")
         if use_none_rcs == True:
             RCS = rcs.rcs_by_name("None")
             RCS.root(self.root)
@@ -354,30 +427,31 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
         return tree_version
 
     def set_version(self):
+        """
+        Requires disk access.
+        """
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("set version")
         self.rcs.mkdir(self.get_path())
         self.rcs.set_file_contents(self.get_path("version"),
                                    TREE_VERSION_STRING)
 
-    def get_path(self, *args):
-        my_dir = os.path.join(self.root, ".be")
-        if len(args) == 0:
-            return my_dir
-        assert args[0] in ["version", "settings", "bugs"], str(args)
-        return os.path.join(my_dir, *args)
+    # methods controlling disk access
 
-    def _guess_rcs(self, allow_rcs_init=False):
-        deepdir = self.get_path()
-        if not os.path.exists(deepdir):
-            deepdir = os.path.dirname(deepdir)
-        new_rcs = rcs.detect_rcs(deepdir)
-        install = False
-        if new_rcs.name == "None":
-            if allow_rcs_init == True:
-                new_rcs = rcs.installed_rcs()
-                new_rcs.init(self.root)
-        return new_rcs
+    def set_sync_with_disk(self, value):
+        """
+        Adjust .sync_with_disk for the BugDir and all it's children.
+        See the BugDir docstring for a description of the role of
+        .sync_with_disk.
+        """
+        self.sync_with_disk = value
+        for bug in self:
+            bug.set_sync_with_disk(value)
 
     def load(self):
+        """
+        Reqires disk access
+        """
         version = self.get_version(use_none_rcs=True)
         if version != TREE_VERSION_STRING:
             raise NotImplementedError, \
@@ -387,59 +461,43 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
                 raise NoBugDir(self.get_path())
             self.load_settings()
 
-            self.rcs = rcs.rcs_by_name(self.rcs_name)
-            self._setup_user_id(self.user_id)
-
     def load_all_bugs(self):
-        "Warning: this could take a while."
+        """
+        Requires disk access.
+        Warning: this could take a while.
+        """
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("load all bugs")
         self._clear_bugs()
         for uuid in self.list_uuids():
             self._load_bug(uuid)
 
     def save(self):
         """
+        Note that this command writes to disk _regardless_ of the
+        status of .sync_with_disk.
+
         Save any loaded contents to disk.  Because of lazy loading of
         bugs and comments, this is actually not too inefficient.
 
-        However, if self.sync_with_disk = True, then any changes are
+        However, if .sync_with_disk = True, then any changes are
         automatically written to disk as soon as they happen, so
         calling this method will just waste time (unless something
         else has been messing with your on-disk files).
+
+        Requires disk access.
         """
+        sync_with_disk = self.sync_with_disk
+        if sync_with_disk == False:
+            self.set_sync_with_disk(True)
         self.set_version()
         self.save_settings()
         for bug in self:
             bug.save()
+        if sync_with_disk == False:
+            self.set_sync_with_disk(sync_with_disk)
 
-    def load_settings(self):
-        self.settings = self._get_settings(self.get_path("settings"))
-        self._setup_saved_settings()
-        self._setup_user_id(self.user_id)
-        self._setup_encoding(self.encoding)
-        self._setup_severities(self.severities)
-        self._setup_status(self.active_status, self.inactive_status)
-
-    def _get_settings(self, settings_path):
-        allow_no_rcs = not self.rcs.path_in_root(settings_path)
-        # allow_no_rcs=True should only be for the special case of
-        # configuring duplicate bugdir settings
-
-        try:
-            settings = mapfile.map_load(self.rcs, settings_path, allow_no_rcs)
-        except rcs.NoSuchFile:
-            settings = {"rcs_name": "None"}
-        return settings
-
-    def save_settings(self):
-        settings = self._get_saved_settings()
-        self._save_settings(self.get_path("settings"), settings)
-
-    def _save_settings(self, settings_path, settings):
-        allow_no_rcs = not self.rcs.path_in_root(settings_path)
-        # allow_no_rcs=True should only be for the special case of
-        # configuring duplicate bugdir settings
-        self.rcs.mkdir(self.get_path(), allow_no_rcs)
-        mapfile.map_save(self.rcs, settings_path, settings, allow_no_rcs)
+    # methods for managing duplicate BugDirs
 
     def duplicate_bugdir(self, revision):
         duplicate_path = self.rcs.duplicate_repo(revision)
@@ -448,23 +506,27 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
         # initialized for versioning
         duplicate_settings_path = os.path.join(duplicate_path,
                                                ".be", "settings")
-        duplicate_settings = self._get_settings(duplicate_settings_path)
+        duplicate_settings = self._get_settings(duplicate_settings_path,
+                                                for_duplicate_bugdir=True)
         if "rcs_name" in duplicate_settings:
             duplicate_settings["rcs_name"] = "None"
             duplicate_settings["user_id"] = self.user_id
         if "disabled" in bug.status_values:
             # Hack to support old versions of BE bugs
             duplicate_settings["inactive_status"] = self.inactive_status
-        self._save_settings(duplicate_settings_path, duplicate_settings)
+        self._save_settings(duplicate_settings_path, duplicate_settings,
+                            for_duplicate_bugdir=True)
 
         return BugDir(duplicate_path, from_disk=True, manipulate_encodings=self._manipulate_encodings)
 
     def remove_duplicate_bugdir(self):
         self.rcs.remove_duplicate_repo()
 
+    # methods for managing bugs
+
     def list_uuids(self):
         uuids = []
-        if os.path.exists(self.get_path()):
+        if self.sync_with_disk == True and os.path.exists(self.get_path()):
             # list the uuids on disk
             for uuid in os.listdir(self.get_path("bugs")):
                 if not (uuid.startswith('.')):
@@ -482,6 +544,8 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
         self._bug_map_gen()
 
     def _load_bug(self, uuid):
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("_load bug")
         bg = bug.Bug(bugdir=self, uuid=uuid, from_disk=True)
         self.append(bg)
         self._bug_map_gen()
@@ -498,7 +562,8 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
 
     def remove_bug(self, bug):
         self.remove(bug)
-        bug.remove()
+        if bug.sync_with_disk == True:
+            bug.remove()
 
     def bug_shortname(self, bug):
         """
@@ -520,7 +585,7 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
 
     def bug_from_shortname(self, shortname):
         """
-        >>> bd = simple_bug_dir()
+        >>> bd = simple_bug_dir(sync_with_disk=False)
         >>> bug_a = bd.bug_from_shortname('a')
         >>> print type(bug_a)
         <class 'libbe.bug.Bug'>
@@ -554,20 +619,31 @@ settings easy.  Don't set this attribute.  Set .rcs instead, and
         return True
 
 
-def simple_bug_dir():
+def simple_bug_dir(sync_with_disk=True):
     """
-    For testing
+    For testing.  Set sync_with_disk==False for a memory-only bugdir.
     >>> bugdir = simple_bug_dir()
-    >>> ls = list(bugdir.list_uuids())
-    >>> ls.sort()
-    >>> print ls
+    >>> uuids = list(bugdir.list_uuids())
+    >>> uuids.sort()
+    >>> print uuids
     ['a', 'b']
     """
-    dir = utility.Dir()
-    assert os.path.exists(dir.path)
-    bugdir = BugDir(dir.path, sink_to_existing_root=False, allow_rcs_init=True,
+    if sync_with_disk == True:
+        dir = utility.Dir()
+        assert os.path.exists(dir.path)
+        root = dir.path
+        assert_new_BugDir = True
+        rcs_init = True
+    else:
+        root = "/"
+        assert_new_BugDir = False
+        rcs_init = False
+    bugdir = BugDir(root, sink_to_existing_root=False,
+                    assert_new_BugDir=assert_new_BugDir,
+                    allow_rcs_init=rcs_init,
                     manipulate_encodings=False)
-    bugdir._dir_ref = dir # postpone cleanup since dir.__del__() removes dir.
+    if sync_with_disk == True: # postpone cleanup since dir.__del__() removes dir.
+        bugdir._dir_ref = dir
     bug_a = bugdir.new_bug("a", summary="Bug A")
     bug_a.creator = "John Doe <jdoe@example.com>"
     bug_a.time = 0
@@ -575,13 +651,13 @@ def simple_bug_dir():
     bug_b.creator = "Jane Doe <jdoe@example.com>"
     bug_b.time = 0
     bug_b.status = "closed"
-    bugdir.save()
+    if sync_with_disk == True:
+        bugdir.save()
+        bugdir.set_sync_with_disk(True)
     return bugdir
 
 
 class BugDirTestCase(unittest.TestCase):
-    def __init__(self, *args, **kwargs):
-        unittest.TestCase.__init__(self, *args, **kwargs)
     def setUp(self):
         self.dir = utility.Dir()
         self.bugdir = BugDir(self.dir.path, sink_to_existing_root=False,
@@ -651,9 +727,12 @@ class BugDirTestCase(unittest.TestCase):
         rep.new_reply("And they have six legs.")
         if sync_with_disk == False:
             self.bugdir.save()
+            self.bugdir.set_sync_with_disk(True)
         self.bugdir._clear_bugs()
         bug = self.bugdir.bug_from_uuid("a")
         bug.load_comments()
+        if sync_with_disk == False:
+            self.bugdir.set_sync_with_disk(False)
         self.failUnless(len(bug.comment_root)==1, len(bug.comment_root))
         for index,comment in enumerate(bug.comments()):
             if index == 0:
@@ -661,7 +740,6 @@ class BugDirTestCase(unittest.TestCase):
                 self.failUnless(repLoaded.uuid == rep.uuid, repLoaded.uuid)
                 self.failUnless(comment.sync_with_disk == True,
                                 comment.sync_with_disk)
-                #load_settings()
                 self.failUnless(comment.content_type == "text/plain",
                                 comment.content_type)
                 self.failUnless(repLoaded.settings["Content-type"]=="text/plain",
@@ -678,5 +756,42 @@ class BugDirTestCase(unittest.TestCase):
     def testSyncedComments(self):
         self.testComments(sync_with_disk=True)
 
-unitsuite = unittest.TestLoader().loadTestsFromTestCase(BugDirTestCase)
-suite = unittest.TestSuite([unitsuite])#, doctest.DocTestSuite()])
+class SimpleBugDirTestCase (unittest.TestCase):
+    def setUp(self):
+        # create a pre-existing bugdir in a temporary directory
+        self.dir = utility.Dir()
+        os.chdir(self.dir.path)
+        self.bugdir = BugDir(self.dir.path, sink_to_existing_root=False,
+                             allow_rcs_init=True)
+        self.bugdir.new_bug("preexisting", summary="Hopefully not imported")
+        self.bugdir.save()
+    def tearDown(self):
+        self.dir.cleanup()
+    def testOnDiskCleanLoad(self):
+        """simple_bug_dir(sync_with_disk==True) should not import preexisting bugs."""
+        bugdir = simple_bug_dir(sync_with_disk=True)
+        self.failUnless(bugdir.sync_with_disk==True, bugdir.sync_with_disk)
+        uuids = sorted([bug.uuid for bug in bugdir])
+        self.failUnless(uuids == ['a', 'b'], uuids)
+        bugdir._clear_bugs()
+        uuids = sorted([bug.uuid for bug in bugdir])
+        self.failUnless(uuids == [], uuids)
+        bugdir.load_all_bugs()
+        uuids = sorted([bug.uuid for bug in bugdir])
+        self.failUnless(uuids == ['a', 'b'], uuids)
+    def testInMemoryCleanLoad(self):
+        """simple_bug_dir(sync_with_disk==False) should not import preexisting bugs."""
+        bugdir = simple_bug_dir(sync_with_disk=False)
+        self.failUnless(bugdir.sync_with_disk==False, bugdir.sync_with_disk)
+        uuids = sorted([bug.uuid for bug in bugdir])
+        self.failUnless(uuids == ['a', 'b'], uuids)
+        self.failUnlessRaises(DiskAccessRequired, bugdir.load_all_bugs)
+        uuids = sorted([bug.uuid for bug in bugdir])
+        self.failUnless(uuids == ['a', 'b'], uuids)
+        bugdir._clear_bugs()
+        uuids = sorted([bug.uuid for bug in bugdir])
+        self.failUnless(uuids == [], uuids)
+
+
+unitsuite = unittest.TestLoader().loadTestsFromModule(sys.modules[__name__])
+suite = unittest.TestSuite([unitsuite, doctest.DocTestSuite()])
diff --git a/libbe/bzr.py b/libbe/bzr.py
index d7cd1e5..7457815 100644
--- a/libbe/bzr.py
+++ b/libbe/bzr.py
@@ -93,6 +93,28 @@ class Bzr(RCS):
         assert len(match.groups()) == 1
         revision = match.groups()[0]
         return revision
+    def _rcs_revision_id(self, index):
+        status,output,error = self._u_invoke_client("revno")
+        current_revision = int(output)
+        if index >= current_revision or index < -current_revision:
+            return None
+        if index >= 0:
+            return str(index+1) # bzr commit 0 is the empty tree.
+        return str(current_revision+index+1)
+    def postcommit(self):
+        try:
+            self._u_invoke_client('merge')
+        except rcs.CommandError, e:
+            if ('No merge branch known or specified' in e.err_str or
+                'No merge location known or specified' in e.err_str):
+                pass
+            else:
+                self._u_invoke_client('revert',  '--no-backup', 
+                                   directory=directory)
+                self._u_invoke_client('resolve', '--all', directory=directory)
+                raise
+        if len(self._u_invoke_client('status', directory=directory)[1]) > 0:
+            self.commit('Merge from upstream')
 
     
 rcs.make_rcs_testcase_subclasses(Bzr, sys.modules[__name__])
diff --git a/libbe/cmdutil.py b/libbe/cmdutil.py
index 35d2f9e..94a6856 100644
--- a/libbe/cmdutil.py
+++ b/libbe/cmdutil.py
@@ -70,10 +70,11 @@ def get_command(command_name):
     return cmd
 
 
-def execute(cmd, args):
+def execute(cmd, args, manipulate_encodings=True):
     enc = encoding.get_encoding()
     cmd = get_command(cmd)
-    ret = cmd.execute([a.decode(enc) for a in args])
+    ret = cmd.execute([a.decode(enc) for a in args],
+                      manipulate_encodings=manipulate_encodings)
     if ret == None:
         ret = 0
     return ret
diff --git a/libbe/comment.py b/libbe/comment.py
index 3249e8b..c5bec43 100644
--- a/libbe/comment.py
+++ b/libbe/comment.py
@@ -61,6 +61,11 @@ class MissingReference(ValueError):
         self.reference = comment.in_reply_to
         self.comment = comment
 
+class DiskAccessRequired (Exception):
+    def __init__(self, goal):
+        msg = "Cannot %s without accessing the disk" % goal
+        Exception.__init__(self, msg)
+
 INVALID_UUID = "!!~~\n INVALID-UUID \n~~!!"
 
 def list_to_root(comments, bug, root=None,
@@ -115,6 +120,8 @@ def loadComments(bug, load_full=False):
     Set load_full=True when you want to load the comment completely
     from disk *now*, rather than waiting and lazy loading as required.
     """
+    if bug.sync_with_disk == False:
+        raise DiskAccessRequired("load comments")
     path = bug.get_path("comments")
     if not os.path.isdir(path):
         return Comment(bug, uuid=INVALID_UUID)
@@ -131,6 +138,8 @@ def loadComments(bug, load_full=False):
     return list_to_root(comments, bug)
 
 def saveComments(bug):
+    if bug.sync_with_disk == False:
+        raise DiskAccessRequired("save comments")
     for comment in bug.comment_root.traverse():
         comment.save()
 
@@ -162,9 +171,9 @@ class Comment(Tree, settings_object.SavedSettingsObject):
                          doc="Alternate ID for linking imported comments.  Internally comments are linked (via In-reply-to) to the parent's UUID.  However, these UUIDs are generated internally, so Alt-id is provided as a user-controlled linking target.")
     def alt_id(): return {}
 
-    @_versioned_property(name="From",
+    @_versioned_property(name="Author",
                          doc="The author of the comment")
-    def From(): return {}
+    def author(): return {}
 
     @_versioned_property(name="In-reply-to",
                          doc="UUID for parent comment or bug")
@@ -178,17 +187,17 @@ class Comment(Tree, settings_object.SavedSettingsObject):
 
     @_versioned_property(name="Date",
                          doc="An RFC 2822 timestamp for comment creation")
-    def time_string(): return {}
+    def date(): return {}
 
     def _get_time(self):
-        if self.time_string == None:
+        if self.date == None:
             return None
-        return utility.str_to_time(self.time_string)
+        return utility.str_to_time(self.date)
     def _set_time(self, value):
-        self.time_string = utility.time_to_str(value)
+        self.date = utility.time_to_str(value)
     time = property(fget=_get_time,
                     fset=_set_time,
-                    doc="An integer version of .time_string")
+                    doc="An integer version of .date")
 
     def _get_comment_body(self):
         if self.rcs != None and self.sync_with_disk == True:
@@ -258,12 +267,28 @@ class Comment(Tree, settings_object.SavedSettingsObject):
                 self.uuid = uuid_gen()
             self.time = int(time.time()) # only save to second precision
             if self.rcs != None:
-                self.From = self.rcs.get_user_id()
+                self.author = self.rcs.get_user_id()
             self.in_reply_to = in_reply_to
             self.body = body
 
-    def set_sync_with_disk(self, value):
-        self.sync_with_disk = True
+    def __cmp__(self, other):
+        return cmp_full(self, other)
+
+    def __str__(self):
+        """
+        >>> comm = Comment(bug=None, body="Some insightful remarks")
+        >>> comm.uuid = "com-1"
+        >>> comm.date = "Thu, 20 Nov 2008 15:55:11 +0000"
+        >>> comm.author = "Jane Doe <jdoe@example.com>"
+        >>> print comm
+        --------- Comment ---------
+        Name: com-1
+        From: Jane Doe <jdoe@example.com>
+        Date: Thu, 20 Nov 2008 15:55:11 +0000
+        <BLANKLINE>
+        Some insightful remarks
+        """
+        return self.string()
 
     def traverse(self, *args, **kwargs):
         """Avoid working with the possible dummy root comment"""
@@ -272,6 +297,8 @@ class Comment(Tree, settings_object.SavedSettingsObject):
                 continue
             yield comment
 
+    # serializing methods
+
     def _setting_attr_string(self, setting):
         value = getattr(self, setting)
         if value == None:
@@ -282,12 +309,12 @@ class Comment(Tree, settings_object.SavedSettingsObject):
         """
         >>> comm = Comment(bug=None, body="Some\\ninsightful\\nremarks\\n")
         >>> comm.uuid = "0123"
-        >>> comm.time_string = "Thu, 01 Jan 1970 00:00:00 +0000"
+        >>> comm.date = "Thu, 01 Jan 1970 00:00:00 +0000"
         >>> print comm.xml(indent=2, shortname="com-1")
           <comment>
             <uuid>0123</uuid>
             <short-name>com-1</short-name>
-            <from></from>
+            <author></author>
             <date>Thu, 01 Jan 1970 00:00:00 +0000</date>
             <content-type>text/plain</content-type>
             <body>Some
@@ -309,8 +336,8 @@ class Comment(Tree, settings_object.SavedSettingsObject):
                 ("alt-id", self.alt_id),
                 ("short-name", shortname),
                 ("in-reply-to", self.in_reply_to),
-                ("from", self._setting_attr_string("From")),
-                ("date", self.time_string),
+                ("author", self._setting_attr_string("author")),
+                ("date", self.date),
                 ("content-type", self.content_type),
                 ("body", body)]
         lines = ["<comment>"]
@@ -328,11 +355,11 @@ class Comment(Tree, settings_object.SavedSettingsObject):
         <alt-id> fields.
         >>> commA = Comment(bug=None, body="Some\\ninsightful\\nremarks\\n")
         >>> commA.uuid = "0123"
-        >>> commA.time_string = "Thu, 01 Jan 1970 00:00:00 +0000"
+        >>> commA.date = "Thu, 01 Jan 1970 00:00:00 +0000"
         >>> xml = commA.xml(shortname="com-1")
         >>> commB = Comment()
         >>> commB.from_xml(xml)
-        >>> attrs=['uuid','alt_id','in_reply_to','From','time_string','content_type','body']
+        >>> attrs=['uuid','alt_id','in_reply_to','author','date','content_type','body']
         >>> for attr in attrs: # doctest: +ELLIPSIS
         ...     if getattr(commB, attr) != getattr(commA, attr):
         ...         estr = "Mismatch on %s: '%s' should be '%s'"
@@ -342,15 +369,15 @@ class Comment(Tree, settings_object.SavedSettingsObject):
         Mismatch on alt_id: '0123' should be 'None'
         >>> print commB.alt_id
         0123
-        >>> commA.From
-        >>> commB.From
+        >>> commA.author
+        >>> commB.author
         """
         if type(xml_string) == types.UnicodeType:
             xml_string = xml_string.strip().encode("unicode_escape")
         comment = ElementTree.XML(xml_string)
         if comment.tag != "comment":
             raise InvalidXML(comment, "root element must be <comment>")
-        tags=['uuid','alt-id','in-reply-to','from','date','content-type','body']
+        tags=['uuid','alt-id','in-reply-to','author','date','content-type','body']
         uuid = None
         body = None
         for child in comment.getchildren():
@@ -368,10 +395,6 @@ class Comment(Tree, settings_object.SavedSettingsObject):
                 if child.tag == "body":
                     body = text
                     continue # don't set the bug's body yet.
-                elif child.tag == 'from':
-                    attr_name = "From"
-                elif child.tag == 'date':
-                    attr_name = 'time_string'
                 else:
                     attr_name = child.tag.replace('-','_')
                 setattr(self, attr_name, text)
@@ -389,7 +412,7 @@ class Comment(Tree, settings_object.SavedSettingsObject):
     def string(self, indent=0, shortname=None):
         """
         >>> comm = Comment(bug=None, body="Some\\ninsightful\\nremarks\\n")
-        >>> comm.time_string = "Thu, 01 Jan 1970 00:00:00 +0000"
+        >>> comm.date = "Thu, 01 Jan 1970 00:00:00 +0000"
         >>> print comm.string(indent=2, shortname="com-1")
           --------- Comment ---------
           Name: com-1
@@ -405,8 +428,8 @@ class Comment(Tree, settings_object.SavedSettingsObject):
         lines = []
         lines.append("--------- Comment ---------")
         lines.append("Name: %s" % shortname)
-        lines.append("From: %s" % (self._setting_attr_string("From")))
-        lines.append("Date: %s" % self.time_string)
+        lines.append("From: %s" % (self._setting_attr_string("author")))
+        lines.append("Date: %s" % self.date)
         lines.append("")
         if self.content_type.startswith("text/"):
             lines.extend((self.body or "").splitlines())
@@ -417,78 +440,6 @@ class Comment(Tree, settings_object.SavedSettingsObject):
         sep = '\n' + istring
         return istring + sep.join(lines).rstrip('\n')
 
-    def __str__(self):
-        """
-        >>> comm = Comment(bug=None, body="Some insightful remarks")
-        >>> comm.uuid = "com-1"
-        >>> comm.time_string = "Thu, 20 Nov 2008 15:55:11 +0000"
-        >>> comm.From = "Jane Doe <jdoe@example.com>"
-        >>> print comm
-        --------- Comment ---------
-        Name: com-1
-        From: Jane Doe <jdoe@example.com>
-        Date: Thu, 20 Nov 2008 15:55:11 +0000
-        <BLANKLINE>
-        Some insightful remarks
-        """
-        return self.string()
-
-    def get_path(self, name=None):
-        my_dir = os.path.join(self.bug.get_path("comments"), self.uuid)
-        if name is None:
-            return my_dir
-        assert name in ["values", "body"]
-        return os.path.join(my_dir, name)
-
-    def load_settings(self):
-        self.settings = mapfile.map_load(self.rcs, self.get_path("values"))
-        self._setup_saved_settings()
-
-    def save_settings(self):
-        self.rcs.mkdir(self.get_path())
-        path = self.get_path("values")
-        mapfile.map_save(self.rcs, path, self._get_saved_settings())
-
-    def save(self):
-        """
-        Save any loaded contents to disk.
-        
-        However, if self.sync_with_disk = True, then any changes are
-        automatically written to disk as soon as they happen, so
-        calling this method will just waste time (unless something
-        else has been messing with your on-disk files).
-        """
-        assert self.body != None, "Can't save blank comment"
-        self.save_settings()
-        self._set_comment_body(new=self.body, force=True)
-
-    def remove(self):
-        for comment in self.traverse():
-            path = comment.get_path()
-            self.rcs.recursive_remove(path)
-
-    def add_reply(self, reply, allow_time_inversion=False):
-        if self.uuid != INVALID_UUID:
-            reply.in_reply_to = self.uuid
-        self.append(reply)
-        #raise Exception, "adding reply \n%s\n%s" % (self, reply)
-
-    def new_reply(self, body=None):
-        """
-        >>> comm = Comment(bug=None, body="Some insightful remarks")
-        >>> repA = comm.new_reply("Critique original comment")
-        >>> repB = repA.new_reply("Begin flamewar :p")
-        >>> repB.in_reply_to == repA.uuid
-        True
-        """
-        reply = Comment(self.bug, body=body)
-        if self.bug != None:
-            reply.set_sync_with_disk(self.bug.sync_with_disk)
-        if reply.sync_with_disk == True:
-            reply.save()
-        self.add_reply(reply)
-        return reply
-
     def string_thread(self, string_method_name="string", name_map={},
                       indent=0, flatten=True,
                       auto_name_map=False, bug_shortname=None):
@@ -506,7 +457,7 @@ class Comment(Tree, settings_object.SavedSettingsObject):
           name_map = {}
           for shortname,comment in comm.comment_shortnames(bug_shortname):
               name_map[comment.uuid] = shortname
-          comm.sort(key=lambda c : c.From) # your sort
+          comm.sort(key=lambda c : c.author) # your sort
           comm.string_thread(name_map=name_map)
 
         >>> a = Comment(bug=None, uuid="a", body="Insightful remarks")
@@ -593,6 +544,80 @@ class Comment(Tree, settings_object.SavedSettingsObject):
                                   indent=indent, auto_name_map=auto_name_map,
                                   bug_shortname=bug_shortname)
 
+    # methods for saving/loading/acessing settings and properties.
+
+    def get_path(self, name=None):
+        my_dir = os.path.join(self.bug.get_path("comments"), self.uuid)
+        if name is None:
+            return my_dir
+        assert name in ["values", "body"]
+        return os.path.join(my_dir, name)
+
+    def set_sync_with_disk(self, value):
+        self.sync_with_disk = value
+
+    def load_settings(self):
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("load settings")
+        self.settings = mapfile.map_load(self.rcs, self.get_path("values"))
+        # hack to deal with old BE comments:
+        if "From" in self.settings:
+            self.settings["Author"] = self.settings.pop("From")
+        self._setup_saved_settings()
+
+    def save_settings(self):
+        if self.sync_with_disk == False:
+            raise DiskAccessRequired("save settings")
+        self.rcs.mkdir(self.get_path())
+        path = self.get_path("values")
+        mapfile.map_save(self.rcs, path, self._get_saved_settings())
+
+    def save(self):
+        """
+        Save any loaded contents to disk.
+        
+        However, if self.sync_with_disk = True, then any changes are
+        automatically written to disk as soon as they happen, so
+        calling this method will just waste time (unless something
+        else has been messing with your on-disk files).
+        """
+        sync_with_disk = self.sync_with_disk
+        if sync_with_disk == False:
+            self.set_sync_with_disk(True)
+        assert self.body != None, "Can't save blank comment"
+        self.save_settings()
+        self._set_comment_body(new=self.body, force=True)
+        if sync_with_disk == False:
+            self.set_sync_with_disk(False)
+
+    def remove(self):
+        if self.sync_with_disk == False and self.uuid != INVALID_UUID:
+            raise DiskAccessRequired("remove")
+        for comment in self.traverse():
+            path = comment.get_path()
+            self.rcs.recursive_remove(path)
+
+    def add_reply(self, reply, allow_time_inversion=False):
+        if self.uuid != INVALID_UUID:
+            reply.in_reply_to = self.uuid
+        self.append(reply)
+
+    def new_reply(self, body=None):
+        """
+        >>> comm = Comment(bug=None, body="Some insightful remarks")
+        >>> repA = comm.new_reply("Critique original comment")
+        >>> repB = repA.new_reply("Begin flamewar :p")
+        >>> repB.in_reply_to == repA.uuid
+        True
+        """
+        reply = Comment(self.bug, body=body)
+        if self.bug != None:
+            reply.set_sync_with_disk(self.bug.sync_with_disk)
+        if reply.sync_with_disk == True:
+            reply.save()
+        self.add_reply(reply)
+        return reply
+
     def comment_shortnames(self, bug_shortname=None):
         """
         Iterate through (id, comment) pairs, in time order.
@@ -659,4 +684,59 @@ class Comment(Tree, settings_object.SavedSettingsObject):
                 return comment
         raise KeyError(uuid)
 
+def cmp_attr(comment_1, comment_2, attr, invert=False):
+    """
+    Compare a general attribute between two comments using the conventional
+    comparison rule for that attribute type.  If invert == True, sort
+    *against* that convention.
+    >>> attr="author"
+    >>> commentA = Comment()
+    >>> commentB = Comment()
+    >>> commentA.author = "John Doe"
+    >>> commentB.author = "Jane Doe"
+    >>> cmp_attr(commentA, commentB, attr) < 0
+    True
+    >>> cmp_attr(commentA, commentB, attr, invert=True) > 0
+    True
+    >>> commentB.author = "John Doe"
+    >>> cmp_attr(commentA, commentB, attr) == 0
+    True
+    """
+    if not hasattr(comment_2, attr) :
+        return 1
+    val_1 = getattr(comment_1, attr)
+    val_2 = getattr(comment_2, attr)
+    if val_1 == None: val_1 = None
+    if val_2 == None: val_2 = None
+    
+    if invert == True :
+        return -cmp(val_1, val_2)
+    else :
+        return cmp(val_1, val_2)
+
+# alphabetical rankings (a < z)
+cmp_uuid = lambda comment_1, comment_2 : cmp_attr(comment_1, comment_2, "uuid")
+cmp_author = lambda comment_1, comment_2 : cmp_attr(comment_1, comment_2, "author")
+cmp_in_reply_to = lambda comment_1, comment_2 : cmp_attr(comment_1, comment_2, "in_reply_to")
+cmp_content_type = lambda comment_1, comment_2 : cmp_attr(comment_1, comment_2, "content_type")
+cmp_body = lambda comment_1, comment_2 : cmp_attr(comment_1, comment_2, "body")
+# chronological rankings (newer < older)
+cmp_time = lambda comment_1, comment_2 : cmp_attr(comment_1, comment_2, "time", invert=True)
+
+DEFAULT_CMP_FULL_CMP_LIST = \
+    (cmp_time, cmp_author, cmp_content_type, cmp_body, cmp_in_reply_to,
+     cmp_uuid)
+
+class CommentCompoundComparator (object):
+    def __init__(self, cmp_list=DEFAULT_CMP_FULL_CMP_LIST):
+        self.cmp_list = cmp_list
+    def __call__(self, comment_1, comment_2):
+        for comparison in self.cmp_list :
+            val = comparison(comment_1, comment_2)
+            if val != 0 :
+                return val
+        return 0
+        
+cmp_full = CommentCompoundComparator()
+
 suite = doctest.DocTestSuite()
diff --git a/libbe/darcs.py b/libbe/darcs.py
index e7132c0..0720ed9 100644
--- a/libbe/darcs.py
+++ b/libbe/darcs.py
@@ -18,8 +18,13 @@ import codecs
 import os
 import re
 import sys
-import unittest
+try: # import core module, Python >= 2.5
+    from xml.etree import ElementTree
+except ImportError: # look for non-core module
+    from elementtree import ElementTree
+from xml.sax.saxutils import unescape
 import doctest
+import unittest
 
 import rcs
 from rcs import RCS
@@ -138,24 +143,36 @@ class Darcs(RCS):
         args = ['record', '--all', '--author', id, '--logfile', commitfile]
         status,output,error = self._u_invoke_client(*args)
         empty_strings = ["No changes!"]
-        revision = None
         if self._u_any_in_string(empty_strings, output) == True:
             if allow_empty == False:
                 raise rcs.EmptyCommit()
-            else: # we need a extra call to get the current revision
-                args = ["changes", "--last=1", "--xml"]
-                status,output,error = self._u_invoke_client(*args)
-                revline = re.compile("[ \t]*<name>(.*)</name>")
-                # note that darcs does _not_ make an empty revision.
-                # this returns the last non-empty revision id...
+            # note that darcs does _not_ make an empty revision.
+            # this returns the last non-empty revision id...
+            revision = self._rcs_revision_id(-1)
         else:
             revline = re.compile("Finished recording patch '(.*)'")
-        match = revline.search(output)
-        assert match != None, output+error
-        assert len(match.groups()) == 1
-        revision = match.groups()[0]
+            match = revline.search(output)
+            assert match != None, output+error
+            assert len(match.groups()) == 1
+            revision = match.groups()[0]
         return revision
-
+    def _rcs_revision_id(self, index):
+        status,output,error = self._u_invoke_client("changes", "--xml")
+        revisions = []
+        xml_str = output.encode("unicode_escape").replace(r"\n", "\n")
+        element = ElementTree.XML(xml_str)
+        assert element.tag == "changelog", element.tag
+        for patch in element.getchildren():
+            assert patch.tag == "patch", patch.tag
+            for child in patch.getchildren():
+                if child.tag == "name":
+                    text = unescape(unicode(child.text).decode("unicode_escape").strip())
+                    revisions.append(text)
+        revisions.reverse()
+        try:
+            return revisions[index]
+        except IndexError:
+            return None
     
 rcs.make_rcs_testcase_subclasses(Darcs, sys.modules[__name__])
 
diff --git a/libbe/diff.py b/libbe/diff.py
index ba48efc..69ccff8 100644
--- a/libbe/diff.py
+++ b/libbe/diff.py
@@ -15,111 +15,398 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 """Compare two bug trees"""
-from libbe import cmdutil, bugdir, bug
+from libbe import bugdir, bug, settings_object, tree
 from libbe.utility import time_to_str
+import difflib
 import doctest
 
-def bug_diffs(old_bugdir, new_bugdir):
-    added = []
-    removed = []
-    modified = []
-    for uuid in old_bugdir.list_uuids():
-        old_bug = old_bugdir.bug_from_uuid(uuid)
-        try:
-            new_bug = new_bugdir.bug_from_uuid(uuid)
-            old_bug.load_comments()
-            new_bug.load_comments()
-            if old_bug != new_bug:
-                modified.append((old_bug, new_bug))
-        except KeyError:
-            removed.append(old_bug)
-    for uuid in new_bugdir.list_uuids():
-        if not old_bugdir.has_bug(uuid):
-            new_bug = new_bugdir.bug_from_uuid(uuid)
-            added.append(new_bug)
-    return (removed, modified, added)
+class DiffTree (tree.Tree):
+    """
+    A tree holding difference data for easy report generation.
+    >>> all = DiffTree("all")
+    >>> bugdir = DiffTree("bugdir", data="target: None -> 1.0")
+    >>> all.append(bugdir)
+    >>> bugs = DiffTree("bugs", "bug-count: 5 -> 6")
+    >>> all.append(bugs)
+    >>> new = DiffTree("new", "new bugs: ABC, DEF")
+    >>> bugs.append(new)
+    >>> rem = DiffTree("rem", "removed bugs: RST, UVW")
+    >>> bugs.append(rem)
+    >>> print all.report_string()
+    target: None -> 1.0
+    bug-count: 5 -> 6
+      new bugs: ABC, DEF
+      removed bugs: RST, UVW
+    >>> print "\\n".join(all.paths())
+    all
+    all/bugdir
+    all/bugs
+    all/bugs/new
+    all/bugs/rem
+    >>> all.child_by_path("/") == all
+    True
+    >>> all.child_by_path("/bugs") == bugs
+    True
+    >>> all.child_by_path("/bugs/rem") == rem
+    True
+    >>> all.child_by_path("all") == all
+    True
+    >>> all.child_by_path("all/") == all
+    True
+    >>> all.child_by_path("all/bugs") == bugs
+    True
+    >>> all.child_by_path("/bugs").masked = True
+    >>> print all.report_string()
+    target: None -> 1.0
+    """
+    def __init__(self, name, data=None, data_part_fn=str,
+                 requires_children=False, masked=False):
+        tree.Tree.__init__(self)
+        self.name = name
+        self.data = data
+        self.data_part_fn = data_part_fn
+        self.requires_children = requires_children
+        self.masked = masked
+    def paths(self, parent_path=None):
+        paths = []
+        if parent_path == None:
+            path = self.name
+        else:
+            path = "%s/%s" % (parent_path, self.name)
+        paths.append(path)
+        for child in self:
+            paths.extend(child.paths(path))
+        return paths
+    def child_by_path(self, path):
+        if hasattr(path, "split"): # convert string path to a list of names
+            names = path.split("/")
+            if names[0] == "":
+                names[0] = self.name # replace root with self
+            if len(names) > 1 and names[-1] == "":
+                names = names[:-1] # strip empty tail
+        else: # it was already an array
+            names = path
+        assert len(names) > 0, path
+        if names[0] == self.name:
+            if len(names) == 1:
+                return self
+            for child in self:
+                if names[1] == child.name:
+                    return child.child_by_path(names[1:])
+        if len(names) == 1:
+            raise KeyError, "%s doesn't match '%s'" % (names, self.name)
+        raise KeyError, "%s points to child not in %s" % (names, [c.name for c in self])
+    def report_string(self):
+        return "\n".join(self.report())
+    def report(self, root=None, parent=None, depth=0):
+        if root == None:
+            root = self.make_root()
+        if self.masked == True:
+            return None
+        data_part = self.data_part(depth)
+        if self.requires_children == True and len(self) == 0:
+            pass
+        else:
+            self.join(root, parent, data_part)
+            depth += 1
+        for child in self:
+            child.report(root, self, depth)
+        return root
+    def make_root(self):
+        return []
+    def join(self, root, parent, data_part):
+        if data_part != None:
+            root.append(data_part)
+    def data_part(self, depth, indent=True):
+        if self.data == None:
+            return None
+        if hasattr(self, "_cached_data_part"):
+            return self._cached_data_part
+        data_part = self.data_part_fn(self.data)
+        if indent == True:
+            data_part_lines = data_part.splitlines()
+            indent = "  "*(depth)
+            line_sep = "\n"+indent
+            data_part = indent+line_sep.join(data_part_lines)
+        self._cached_data_part = data_part
+        return data_part
 
-def diff_report(bug_diffs_data, old_bugdir, new_bugdir):
-    bugs_removed,bugs_modified,bugs_added = bug_diffs_data
-    def modified_cmp(left, right):
-        return bug.cmp_severity(left[1], right[1])
+class Diff (object):
+    """
+    Difference tree generator for BugDirs.
+    >>> import copy
+    >>> bd = bugdir.simple_bug_dir(sync_with_disk=False)
+    >>> bd.user_id = "John Doe <j@doe.com>"
+    >>> bd_new = copy.deepcopy(bd)
+    >>> bd_new.target = "1.0"
+    >>> a = bd_new.bug_from_uuid("a")
+    >>> rep = a.comment_root.new_reply("I'm closing this bug")
+    >>> rep.uuid = "acom"
+    >>> rep.date = "Thu, 01 Jan 1970 00:00:00 +0000"
+    >>> a.status = "closed"
+    >>> b = bd_new.bug_from_uuid("b")
+    >>> bd_new.remove_bug(b)
+    >>> c = bd_new.new_bug("c", "Bug C")
+    >>> d = Diff(bd, bd_new)
+    >>> r = d.report_tree()
+    >>> print "\\n".join(r.paths())
+    bugdir
+    bugdir/settings
+    bugdir/bugs
+    bugdir/bugs/new
+    bugdir/bugs/new/c
+    bugdir/bugs/rem
+    bugdir/bugs/rem/b
+    bugdir/bugs/mod
+    bugdir/bugs/mod/a
+    bugdir/bugs/mod/a/settings
+    bugdir/bugs/mod/a/comments
+    bugdir/bugs/mod/a/comments/new
+    bugdir/bugs/mod/a/comments/new/acom
+    bugdir/bugs/mod/a/comments/rem
+    bugdir/bugs/mod/a/comments/mod
+    >>> print r.report_string()
+    Changed bug directory settings:
+      target: None -> 1.0
+    New bugs:
+      c:om: Bug C
+    Removed bugs:
+      b:cm: Bug B
+    Modified bugs:
+      a:cm: Bug A
+        Changed bug settings:
+          status: open -> closed
+        New comments:
+          from John Doe <j@doe.com> on Thu, 01 Jan 1970 00:00:00 +0000
+    """
+    def __init__(self, old_bugdir, new_bugdir):
+        self.old_bugdir = old_bugdir
+        self.new_bugdir = new_bugdir
 
-    bugs_added.sort(bug.cmp_severity)
-    bugs_removed.sort(bug.cmp_severity)
-    bugs_modified.sort(modified_cmp)
-    lines = []
-    
-    if old_bugdir.settings != new_bugdir.settings:
-        bugdir_settings = sorted(new_bugdir.settings_properties)
-        bugdir_settings.remove("rcs_name") # tweaked by bugdir.duplicate_bugdir
-        change_list = change_lines(old_bugdir, new_bugdir, bugdir_settings)
-        if len(change_list) >  0:
-            lines.append("Modified bug directory:")
-            change_strings = ["%s: %s -> %s" % f for f in change_list]
-            lines.extend(change_strings)
-            lines.append("")
-    if len(bugs_added) > 0:
-        lines.append("New bug reports:")
-        for bg in bugs_added:
-            lines.extend(bg.string(shortlist=True).splitlines())
-        lines.append("")
-    if len(bugs_modified) > 0:
-        printed = False
-        for old_bug, new_bug in bugs_modified:
-            change_str = bug_changes(old_bug, new_bug)
-            if change_str is None:
-                continue
-            if not printed:
-                printed = True
-                lines.append("Modified bug reports:")
-            lines.extend(change_str.splitlines())
-        if printed == True:
-            lines.append("")
-    if len(bugs_removed) > 0:
-        lines.append("Removed bug reports:")
-        for bg in bugs_removed:
-            lines.extend(bg.string(shortlist=True).splitlines())
-        lines.append("")
-    
-    return "\n".join(lines).rstrip("\n")
+    # data assembly methods
 
-def change_lines(old, new, attributes):
-    change_list = []    
-    for attr in attributes:
-        old_attr = getattr(old, attr)
-        new_attr = getattr(new, attr)
-        if old_attr != new_attr:
-            change_list.append((attr, old_attr, new_attr))
-    if len(change_list) >= 0:
-        return change_list
-    else:
+    def _changed_bugs(self):
+        """
+        Search for differences in all bugs between .old_bugdir and
+        .new_bugdir.  Returns
+          (added_bugs, modified_bugs, removed_bugs)
+        where added_bugs and removed_bugs are lists of added and
+        removed bugs respectively.  modified_bugs is a list of
+        (old_bug,new_bug) pairs.
+        """
+        if hasattr(self, "__changed_bugs"):
+            return self.__changed_bugs
+        added = []
+        removed = []
+        modified = []
+        for uuid in self.new_bugdir.list_uuids():
+            new_bug = self.new_bugdir.bug_from_uuid(uuid)
+            try:
+                old_bug = self.old_bugdir.bug_from_uuid(uuid)
+            except KeyError:
+                added.append(new_bug)
+            else:
+                if old_bug.sync_with_disk == True:
+                    old_bug.load_comments()
+                if new_bug.sync_with_disk == True:
+                    new_bug.load_comments()
+                if old_bug != new_bug:
+                    modified.append((old_bug, new_bug))
+        for uuid in self.old_bugdir.list_uuids():
+            if not self.new_bugdir.has_bug(uuid):
+                old_bug = self.old_bugdir.bug_from_uuid(uuid)
+                removed.append(old_bug)
+        added.sort()
+        removed.sort()
+        modified.sort(self._bug_modified_cmp)
+        self.__changed_bugs = (added, modified, removed)
+        return self.__changed_bugs
+    def _bug_modified_cmp(self, left, right):
+        return cmp(left[1], right[1])
+    def _changed_comments(self, old, new):
+        """
+        Search for differences in all loaded comments between the bugs
+        old and new.  Returns
+          (added_comments, modified_comments, removed_comments)
+        analogous to ._changed_bugs.
+        """
+        if hasattr(self, "__changed_comments"):
+            if new.uuid in self.__changed_comments:
+                return self.__changed_comments[new.uuid]
+        else:
+            self.__changed_comments = {}
+        added = []
+        removed = []
+        modified = []
+        old.comment_root.sort(key=lambda comm : comm.time)
+        new.comment_root.sort(key=lambda comm : comm.time)
+        old_comment_ids = [c.uuid for c in old.comments()]
+        new_comment_ids = [c.uuid for c in new.comments()]
+        for uuid in new_comment_ids:
+            new_comment = new.comment_from_uuid(uuid)
+            try:
+                old_comment = old.comment_from_uuid(uuid)
+            except KeyError:
+                added.append(new_comment)
+            else:
+                if old_comment != new_comment:
+                    modified.append((old_comment, new_comment))
+        for uuid in old_comment_ids:
+            if uuid not in new_comment_ids:
+                new_comment = new.comment_from_uuid(uuid)
+                removed.append(new_comment)
+        self.__changed_comments[new.uuid] = (added, modified, removed)
+        return self.__changed_comments[new.uuid]
+    def _attribute_changes(self, old, new, attributes):
+        """
+        Take two objects old and new, and compare the value of *.attr
+        for attr in the list attribute names.  Returns a list of
+          (attr_name, old_value, new_value)
+        tuples.
+        """
+        change_list = []
+        for attr in attributes:
+            old_value = getattr(old, attr)
+            new_value = getattr(new, attr)
+            if old_value != new_value:
+                change_list.append((attr, old_value, new_value))
+        if len(change_list) >= 0:
+            return change_list
         return None
+    def _settings_properties_attribute_changes(self, old, new,
+                                              hidden_properties=[]):
+        properties = sorted(new.settings_properties)
+        for p in hidden_properties:
+            properties.remove(p)
+        attributes = [settings_object.setting_name_to_attr_name(None, p)
+                      for p in properties]
+        return self._attribute_changes(old, new, attributes)
+    def _bugdir_attribute_changes(self):
+        return self._settings_properties_attribute_changes( \
+            self.old_bugdir, self.new_bugdir,
+            ["rcs_name"]) # tweaked by bugdir.duplicate_bugdir
+    def _bug_attribute_changes(self, old, new):
+        return self._settings_properties_attribute_changes(old, new)
+    def _comment_attribute_changes(self, old, new):
+        return self._settings_properties_attribute_changes(old, new)
 
-def bug_changes(old, new):
-    bug_settings = sorted(new.settings_properties)
-    change_list = change_lines(old, new, bug_settings)
-    change_strings = ["%s: %s -> %s" % f for f in change_list]
+    # report generation methods
 
-    old_comment_ids = [c.uuid for c in old.comments()]
-    new_comment_ids = [c.uuid for c in new.comments()]
-    for comment_id in new_comment_ids:
-        if comment_id not in old_comment_ids:
-            summary = comment_summary(new.comment_from_uuid(comment_id), "new")
-            change_strings.append(summary)
-    for comment_id in old_comment_ids:
-        if comment_id not in new_comment_ids:
-            summary = comment_summary(new.comment_from_uuid(comment_id),
-                                      "removed")
-            change_strings.append(summary)
+    def report_tree(self, diff_tree=DiffTree):
+        """
+        Pretty bare to make it easy to adjust to specific cases.  You
+        can pass in a DiffTree subclass via diff_tree to override the
+        default report assembly process.
+        """
+        if hasattr(self, "__report_tree"):
+            return self.__report_tree
+        bugdir_settings = sorted(self.new_bugdir.settings_properties)
+        bugdir_settings.remove("rcs_name") # tweaked by bugdir.duplicate_bugdir
+        root = diff_tree("bugdir")
+        bugdir_attribute_changes = self._bugdir_attribute_changes()
+        if len(bugdir_attribute_changes) > 0:
+            bugdir = diff_tree("settings", bugdir_attribute_changes,
+                               self.bugdir_attribute_change_string)
+            root.append(bugdir)
+        bug_root = diff_tree("bugs")
+        root.append(bug_root)
+        add,mod,rem = self._changed_bugs()
+        bnew = diff_tree("new", "New bugs:", requires_children=True)
+        bug_root.append(bnew)
+        for bug in add:
+            b = diff_tree(bug.uuid, bug, self.bug_add_string)
+            bnew.append(b)
+        brem = diff_tree("rem", "Removed bugs:", requires_children=True)
+        bug_root.append(brem)
+        for bug in rem:
+            b = diff_tree(bug.uuid, bug, self.bug_rem_string)
+            brem.append(b)
+        bmod = diff_tree("mod", "Modified bugs:", requires_children=True)
+        bug_root.append(bmod)
+        for old,new in mod:
+            b = diff_tree(new.uuid, (old,new), self.bug_mod_string)
+            bmod.append(b)
+            bug_attribute_changes = self._bug_attribute_changes(old, new)
+            if len(bug_attribute_changes) > 0:
+                bset = diff_tree("settings", bug_attribute_changes,
+                                 self.bug_attribute_change_string)
+                b.append(bset)
+            if old.summary != new.summary:
+                data = (old.summary, new.summary)
+                bsum = diff_tree("summary", data, self.bug_summary_change_string)
+                b.append(bsum)
+            cr = diff_tree("comments")
+            b.append(cr)
+            a,m,d = self._changed_comments(old, new)
+            cnew = diff_tree("new", "New comments:", requires_children=True)
+            for comment in a:
+                c = diff_tree(comment.uuid, comment, self.comment_add_string)
+                cnew.append(c)
+            crem = diff_tree("rem", "Removed comments:",requires_children=True)
+            for comment in d:
+                c = diff_tree(comment.uuid, comment, self.comment_rem_string)
+                crem.append(c)
+            cmod = diff_tree("mod","Modified comments:",requires_children=True)
+            for o,n in m:
+                c = diff_tree(n.uuid, (o,n), self.comment_mod_string)
+                cmod.append(c)
+                comm_attribute_changes = self._comment_attribute_changes(o, n)
+                if len(comm_attribute_changes) > 0:
+                    cset = diff_tree("settings", comm_attribute_changes,
+                                     self.comment_attribute_change_string)
+                if o.body != n.body:
+                    data = (o.body, n.body)
+                    cbody = diff_tree("cbody", data,
+                                      self.comment_body_change_string)
+                    c.append(cbody)
+            cr.extend([cnew, crem, cmod])
+        self.__report_tree = root
+        return self.__report_tree
 
-    if len(change_strings) == 0:
-        return None
-    return "%s\n  %s" % (new.string(shortlist=True),
-                         "  \n".join(change_strings))
+    # change data -> string methods.
+    # Feel free to play with these in subclasses.
 
+    def attribute_change_string(self, attribute_changes, indent=0):
+        indent_string = "  "*indent
+        change_strings = [u"%s: %s -> %s" % f for f in attribute_changes]
+        for i,change_string in enumerate(change_strings):
+            change_strings[i] = indent_string+change_string
+        return u"\n".join(change_strings)
+    def bugdir_attribute_change_string(self, attribute_changes):
+        return "Changed bug directory settings:\n%s" % \
+            self.attribute_change_string(attribute_changes, indent=1)
+    def bug_attribute_change_string(self, attribute_changes):
+        return "Changed bug settings:\n%s" % \
+            self.attribute_change_string(attribute_changes, indent=1)
+    def comment_attribute_change_string(self, attribute_changes):
+        return "Changed comment settings:\n%s" % \
+            self.attribute_change_string(attribute_changes, indent=1)
+    def bug_add_string(self, bug):
+        return bug.string(shortlist=True)
+    def bug_rem_string(self, bug):
+        return bug.string(shortlist=True)
+    def bug_mod_string(self, bugs):
+        old_bug,new_bug = bugs
+        return new_bug.string(shortlist=True)
+    def bug_summary_change_string(self, summaries):
+        old_summary,new_summary = summaries
+        return "summary changed:\n  %s\n  %s" % (old_summary, new_summary)
+    def _comment_summary_string(self, comment):
+        return "from %s on %s" % (comment.author, time_to_str(comment.time))
+    def comment_add_string(self, comment):
+        summary = self._comment_summary_string(comment)
+        first_line = comment.body.splitlines()[0]
+        return "%s\n  %s..." % (summary, first_line)
+    def comment_rem_string(self, comment):
+        summary = self._comment_summary_string(comment)
+        first_line = comment.body.splitlines()[0]
+        return "%s\n  %s..." % (summary, first_line)
+    def comment_mod_string(self, comments):
+        old_comment,new_comment = comments
+        return self._comment_summary_string(new_comment)
+    def comment_body_change_string(self, bodies):
+        old_body,new_body = bodies
+        return difflib.unified_diff(old_body, new_body)
 
-def comment_summary(comment, status):
-    return "%8s comment from %s on %s" % (status, comment.From, 
-                                          time_to_str(comment.time))
 
 suite = doctest.DocTestSuite()
diff --git a/libbe/encoding.py b/libbe/encoding.py
index d603602..4af864e 100644
--- a/libbe/encoding.py
+++ b/libbe/encoding.py
@@ -19,11 +19,15 @@ import locale
 import sys
 import doctest
 
+ENCODING = None # override get_encoding() output by setting this
+
 def get_encoding():
     """
     Guess a useful input/output/filesystem encoding...  Maybe we need
     seperate encodings for input/output and filesystem?  Hmm...
     """
+    if ENCODING != None:
+        return ENCODING
     encoding = locale.getpreferredencoding() or sys.getdefaultencoding()
     if sys.platform != 'win32' or sys.version_info[:2] > (2, 3):
         encoding = locale.getlocale(locale.LC_TIME)[1] or encoding
diff --git a/libbe/git.py b/libbe/git.py
index 2f9ffa9..f7e9646 100644
--- a/libbe/git.py
+++ b/libbe/git.py
@@ -111,7 +111,23 @@ class Git(RCS):
         assert match != None, output+error
         assert len(match.groups()) == 3
         revision = match.groups()[1]
-        return revision
+        full_revision = self._rcs_revision_id(-1)
+        assert full_revision.startswith(revision), \
+            "Mismatched revisions:\n%s\n%s" % (revision, full_revision)
+        return full_revision
+    def _rcs_revision_id(self, index):
+        args = ["rev-list", "--first-parent", "--reverse", "HEAD"]
+        kwargs = {"expect":(0,128)}
+        status,output,error = self._u_invoke_client(*args, **kwargs)
+        if status == 128:
+            if error.startswith("fatal: ambiguous argument 'HEAD': unknown "):
+                return None
+            raise rcs.CommandError(args, status, error)
+        commits = output.splitlines()
+        try:
+            return commits[index]
+        except IndexError:
+            return None
 
     
 rcs.make_rcs_testcase_subclasses(Git, sys.modules[__name__])
diff --git a/libbe/hg.py b/libbe/hg.py
index a20eeb5..31df1d0 100644
--- a/libbe/hg.py
+++ b/libbe/hg.py
@@ -80,14 +80,17 @@ class Hg(RCS):
             strings = ["nothing changed"]
             if self._u_any_in_string(strings, output) == True:
                 raise rcs.EmptyCommit()
-        status,output,error = self._u_invoke_client('identify')
-        revision = None
-        revline = re.compile("(.*) tip")
-        match = revline.search(output)
-        assert match != None, output+error
-        assert len(match.groups()) == 1
-        revision = match.groups()[0]
-        return revision
+        return self._rcs_revision_id(-1)
+    def _rcs_revision_id(self, index, style="id"):
+        args = ["identify", "--rev", str(int(index)), "--%s" % style]
+        kwargs = {"expect": (0,255)}
+        status,output,error = self._u_invoke_client(*args, **kwargs)
+        if status == 0:
+            id = output.strip()
+            if id == '000000000000':
+                return None # before initial commit.
+            return id
+        return None
 
     
 rcs.make_rcs_testcase_subclasses(Hg, sys.modules[__name__])
diff --git a/libbe/properties.py b/libbe/properties.py
index 144220b..09dd20e 100644
--- a/libbe/properties.py
+++ b/libbe/properties.py
@@ -160,10 +160,10 @@ def _get_cached_mutable_property(self, cacher_name, property_name, default=None)
     if (cacher_name, property_name) not in self._mutable_property_cache_copy:
         return default
     return self._mutable_property_cache_copy[(cacher_name, property_name)]
-def _cmp_cached_mutable_property(self, cacher_name, property_name, value):
+def _cmp_cached_mutable_property(self, cacher_name, property_name, value, default=None):
     _init_mutable_property_cache(self)
     if (cacher_name, property_name) not in self._mutable_property_cache_hash:
-        return 1 # any value > non-existant old hash
+        _set_cached_mutable_property(self, cacher_name, property_name, default)
     old_hash = self._mutable_property_cache_hash[(cacher_name, property_name)]
     return cmp(_hash_mutable_value(value), old_hash)
 
@@ -327,7 +327,7 @@ def primed_property(primer, initVal=None):
         return funcs
     return decorator
 
-def change_hook_property(hook, mutable=False):
+def change_hook_property(hook, mutable=False, default=None):
     """
     Call the function hook(instance, old_value, new_value) whenever a
     value different from the current value is set (instance is a a
@@ -359,9 +359,9 @@ def change_hook_property(hook, mutable=False):
                 value = new_value # compare new value with cached
             else:
                 value = fget(self) # compare current value with cached
-            if _cmp_cached_mutable_property(self, "change hook property", name, value) != 0:
+            if _cmp_cached_mutable_property(self, "change hook property", name, value, default) != 0:
                 # there has been a change, cache new value
-                old_value = _get_cached_mutable_property(self, "change hook property", name)
+                old_value = _get_cached_mutable_property(self, "change hook property", name, default)
                 _set_cached_mutable_property(self, "change hook property", name, value)
                 if from_fset == True: # return previously cached value
                     value = old_value
diff --git a/libbe/rcs.py b/libbe/rcs.py
index 294b8e0..0206bf6 100644
--- a/libbe/rcs.py
+++ b/libbe/rcs.py
@@ -214,6 +214,16 @@ class RCS(object):
         changes to commit.
         """
         return None
+    def _rcs_revision_id(self, index):
+        """
+        Return the name of the <index>th revision.  Index will be an
+        integer (possibly <= 0).  The choice of which branch to follow
+        when crossing branches/merges is not defined.
+
+        Return None if revision IDs are not supported, or if the
+        specified revision does not exist.
+        """
+        return None
     def installed(self):
         try:
             self._rcs_help()
@@ -415,6 +425,18 @@ class RCS(object):
         Only executed after successful commits.
         """
         pass
+    def revision_id(self, index=None):
+        """
+        Return the name of the <index>th revision.  The choice of
+        which branch to follow when crossing branches/merges is not
+        defined.
+
+        Return None if index==None, revision IDs are not supported, or
+        if the specified revision does not exist.
+        """
+        if index == None:
+            return None
+        return self._rcs_revision_id(index)
     def _u_any_in_string(self, list, string):
         """
         Return True if any of the strings in list are in string.
@@ -822,6 +844,39 @@ class RCS_commit_TestCase(RCSTestCase):
             self.failUnlessEqual(
                 self.test_contents['rev_1'], committed_contents)
 
+    def test_revision_id_as_committed(self):
+        """Check for compatibility between .commit() and .revision_id()"""
+        if not self.rcs.versioned:
+            self.failUnlessEqual(self.rcs.revision_id(5), None)
+            return
+        committed_revisions = []
+        for path in self.test_files:
+            full_path = self.full_path(path)
+            self.rcs.set_file_contents(
+                full_path, self.test_contents['rev_1'])
+            revision = self.rcs.commit("Initial %s contents." % path)
+            committed_revisions.append(revision)
+            self.rcs.set_file_contents(
+                full_path, self.test_contents['uncommitted'])
+            revision = self.rcs.commit("Altered %s contents." % path)
+            committed_revisions.append(revision)
+        for i,revision in enumerate(committed_revisions):
+            self.failUnlessEqual(self.rcs.revision_id(i), revision)
+            i += -len(committed_revisions) # check negative indices
+            self.failUnlessEqual(self.rcs.revision_id(i), revision)
+        i = len(committed_revisions)
+        self.failUnlessEqual(self.rcs.revision_id(i), None)
+        self.failUnlessEqual(self.rcs.revision_id(-i-1), None)
+
+    def test_revision_id_as_committed(self):
+        """Check revision id before first commit"""
+        if not self.rcs.versioned:
+            self.failUnlessEqual(self.rcs.revision_id(5), None)
+            return
+        committed_revisions = []
+        for path in self.test_files:
+            self.failUnlessEqual(self.rcs.revision_id(0), None)
+
 
 class RCS_duplicate_repo_TestCase(RCSTestCase):
     """Test cases for RCS.duplicate_repo method."""
diff --git a/libbe/settings_object.py b/libbe/settings_object.py
index dde247f..ceea9d5 100644
--- a/libbe/settings_object.py
+++ b/libbe/settings_object.py
@@ -148,7 +148,8 @@ def versioned_property(name, doc,
             checked = checked_property(allowed=allowed)
             fulldoc += "\n\nThe allowed values for this property are: %s." \
                        % (', '.join(allowed))
-        hooked      = change_hook_property(hook=change_hook, mutable=mutable)
+        hooked      = change_hook_property(hook=change_hook, mutable=mutable,
+                                           default=EMPTY)
         primed      = primed_property(primer=primer, initVal=UNPRIMED)
         settings    = settings_property(name=name, null=UNPRIMED)
         docp        = doc_property(doc=fulldoc)
@@ -385,30 +386,24 @@ class SavedSettingsObjectTests(unittest.TestCase):
         self.failUnless(SAVES == [], SAVES)
         self.failUnless(t._settings_loaded == True, t._settings_loaded)
         self.failUnless(t.list_type == None, t.list_type)
-        self.failUnless(SAVES == [
-                "'None' -> '<class 'libbe.settings_object.EMPTY'>'"
-                ], SAVES)
+        self.failUnless(SAVES == [], SAVES)
         self.failUnless(t.settings["List-type"]==EMPTY,t.settings["List-type"])
         t.list_type = []
         self.failUnless(t.settings["List-type"] == [], t.settings["List-type"])
         self.failUnless(SAVES == [
-                "'None' -> '<class 'libbe.settings_object.EMPTY'>'",
                 "'<class 'libbe.settings_object.EMPTY'>' -> '[]'"
                 ], SAVES)
         t.list_type.append(5)
         self.failUnless(SAVES == [
-                "'None' -> '<class 'libbe.settings_object.EMPTY'>'",
                 "'<class 'libbe.settings_object.EMPTY'>' -> '[]'",
                 ], SAVES)
         self.failUnless(t.settings["List-type"] == [5],t.settings["List-type"])
         self.failUnless(SAVES == [ # the append(5) has not yet been saved
-                "'None' -> '<class 'libbe.settings_object.EMPTY'>'",
                 "'<class 'libbe.settings_object.EMPTY'>' -> '[]'",
                 ], SAVES)
         self.failUnless(t.list_type == [5], t.list_type) # <-get triggers saved
 
         self.failUnless(SAVES == [ # now the append(5) has been saved.
-                "'None' -> '<class 'libbe.settings_object.EMPTY'>'",
                 "'<class 'libbe.settings_object.EMPTY'>' -> '[]'",
                 "'[]' -> '[5]'"
                 ], SAVES)